JPH04184718A - Optical disk and optical disk device - Google Patents

Abstract

PURPOSE:To enable accurate detection of the number of tracks traversed by a light beam, by a method wherein a mark indicating an address is formed as a part of pregroove and the pregrooves are formed helically or in the shape of concentric circles so that they are not broken in the direction of circumference. CONSTITUTION:A track 31 is so formed as to be held by two 35-35 between. In a header part 33, the pregrooves 35-35 on the opposite sides of the track 31 are wobbled symmetrically with each other by a width DELTAW toward the outer circumference side or the inner circumference side of an optical magnetic disk 22, and thereby a mark 40 indicating address information is formed. Besides, the pregroove 35 in the header part 33 and a data part 34 are formed in the shape of concentric circles or helically so that they are not broken in the direction of circumference. Accordingly, a light beam 36 always traverses the pregroove 35 when it traverses the track 31, and it can not happen, to the contrary, that the light beam 36 does not traverse the pregroove 35 although it traverses the track 31. According to this constitution, the number of tracks 31 traversed by the light beam can be detected correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disc that records, reproduces, or erases information by irradiating it with a light beam, and an optical disc device that handles the optical disc.

[Conventional technology]

Conventionally, in optical discs, track and sector addresses are generally recorded in a preformat format using uneven marks at the time of manufacture. The optical head of the optical disc device reads the above address while recording, reproducing, and erasing information.

As shown in FIG.
. . , or, as shown in FIG.
4... is formed.

By the way, the operation of accessing a desired track and sector consists of a seek operation in which the optical head is moved in the radial direction to reach a predetermined track, and a predetermined sector is moved to the optical head by rotation of the optical disk after the seek operation. The search (rotation wait) operation is divided into two stages: waiting for the next rotation.

In the optical disc disclosed in Japanese Unexamined Patent Publication No. 54-60823, marks are arranged separately from the pregroove, and when seeking a target track, the mark is located based on a crossing signal detected when crossing the pregroove. The optical head is moved in the radial direction while counting the number of track crossings and calculating the position of the optical head.

[Problem to be solved by the invention]

However, as shown in Figure 27, marks 2, 2...
If the laser beam 5 emitted from the optical head crosses the brig groove 1 as shown by the arrow α, the laser beam 5 will strike the mark 2.
Once over, the signal from mark 2 will be added to the track crossing signal EE (see Figure 28). As a result, if three pulses are generated where two pulses should normally be generated, as shown by the dotted line, or if the interval between bligroove 1 and mark 2 is short, one pulse will be generated across bligroove 1 and mark 2, as shown by the solid line. Sometimes only pulses were generated, causing an error in counting the number of track crossings.

On the other hand, as shown in FIG. 29, when marks 4, 4, etc. are formed by partially interrupting the pregroove 3, when the laser beam 5 passes over the mark 4 in the direction of the arrow α, it crosses the track. Although the track crossing signal EF
There are problems such as not being detected (see Fig. 30).

In addition, in the method described above, in which track and sector addresses are preformatted as uneven marks, the format is fixed, so the user cannot freely change the format after the optical disc is manufactured, making it less versatile. There was a problem that there was a lack of

In contrast, conventionally, floppy disks are soft-formatted by magnetically writing addresses and the like after the disk is manufactured. That is, as shown in FIGS. 31 and 32, the floppy disk 6 has an index hole 7 formed in advance for determining the start position or reference position of soft formatting. And a photointerrupter 8 (detector equipped with a light emitting element and a light receiving element) of the floppy disk device.
As a result, the index hole 7 is detected, and the index hole detection signal U is sent to the information recording/reproducing circuit 10. Based on this, the information recording/reproducing circuit 10 determines the start position or reference position of the soft format.

Then, the recording signal (2) is sent to the magnetic disk 11, and the floppy disk 6 is soft formatted.

By the way, if the soft formatting method of the floppy disk 6 described above is directly applied to an optical disk, the following problems will occur.

In other words, since the optical disk has a recording density that is approximately several ten to several hundred times higher than that of the floppy disk 6, the accuracy of the recording position on the disk is also
Optical discs require precision several tens to hundreds of times higher.

Therefore, even if the index hole 7 as described above is provided on the optical disc, it is impossible to ensure sufficient positional accuracy.

[Means to solve the problem]

In order to solve the above problems, an optical disc according to the present invention includes a pregroove that forms a track for following a light beam, and is formed by wobbling the pregroove or changing the width of the pregroove. A mark indicating an address, and a pregroove including the mark is formed in a concentric or spiral shape without interruption at the same number in the circumference (
Structure of claim 1).

Another optical disc of the present invention includes a pregroove that forms a track for following a light beam, and a soft formatting (soft formatting) formed by wobbling the pregroove or changing the width of the pregroove.
(Means formatting by writing address information etc. using an optical disc device after manufacturing an optical disc)
and an index mark indicating a reference position of the index mark, and the pregroove including the index mark is formed in a concentric or spiral shape without interruption in the circumferential direction. ).

Still another optical disc of the present invention has a first area in which information is recorded in advance, and a second area in which information can be recorded, reproduced, or erased, and the first area has an area for following a light beam. It has a pre-groove forming a track and an information mark recorded in advance by wobbling the pre-groove or changing the width of the pre-groove,
The pre-groove including the information mark is formed in a concentric or spiral shape without interruption in the circumferential direction, and the second area includes a pre-groove forming a track for following the light beam; and an index mark that is formed by wobbling or changing the width of the pregroove and indicating the reference position for soft formatting, and the pregroove including the index mark is formed in a concentric or circular shape without interruption in the circumferential direction. It is characterized by being formed in a spiral shape (configuration according to claim 3).

An optical disc device according to the present invention includes a pregroove that forms a track for a light beam to follow, and a mark indicating an address on the optical disc that is formed by wobbling the pregroove or changing the width of the pregroove. The method uses an optical disc in which a pregroove including the mark is formed concentrically or spirally without interruption in the circumferential direction, reads the mark based on a beam reflected from the optical disc, and reproduces address information. a reproducing means; a track crossing detection means for detecting the crossing of a track by a light beam crossing a pregroove based on a reflected beam from the optical disk when the optical head moves in the radial direction of the optical disk; The present invention is characterized by comprising a counting means for counting, and an optical head moving means for moving the optical head to a target track while calculating the number of moving tracks of the light beam based on the count value of the counting means. Structure of Section 4).

Another optical disc device of the present invention includes a pregroove that forms a track for following a light beam, and a reference position for soft formatting that is formed by wobbling the pregroove or changing the width of the pregroove. An optical disk is used in which a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction, and the index is determined based on the reflected beam from the optical disk. index mark detection means for detecting the mark and outputting an index mark detection signal; formatting means for determining a reference position for soft formatting based on the index mark detection signal and formatting the optical disc;
When the optical head moves in the radial direction of the optical disk, a track crossing detection means detects the crossing of the track by the light beam crossing the pregroove based on the reflected beam from the optical disk, and a counting means counts the number of track crossings. and an optical head moving means for moving the optical head to the target track while calculating the number of moving tracks of the light beam based on the count value of the counting means (configuration according to claim 5). .

Still another optical disc device of the present invention has a first area in which information is recorded in advance, and a second area in which information can be recorded, reproduced, or erased, and the first area is configured to follow a light beam. a pre-groove forming a track, and an information mark recorded in advance by wobbling this pre-groove or changing the width of the pre-groove, and the pre-groove including the information mark is discontinued in the circumferential direction. The second region includes a pregroove that forms a track for the light beam to follow, and the pregroove is formed by wobbling or by changing the width of the pregroove. An optical disc having an index mark indicating a reference position for soft formatting, and a pregroove including the index mark formed concentrically or spirally without interruption in the circumferential direction is used. a reproducing means for reading the information mark based on the reflected beam from one area and reproducing the information; and an index for detecting the index mark based on the reflected beam from the second area of the optical disc and outputting an index mark detection signal. mark detection means;
The reference position for soft formatting is determined based on the index mark detection signal, and the second
A formatting means performs soft formatting of the area, and when the optical head moves in the radial direction of the optical disk, the optical beam crosses the pregroove based on the reflected beam from the optical disk, and detects the crossing of the track. a track crossing detection means; a counting means for counting the number of track crossings; and an optical track movement for moving the optical track to a target track while calculating the number of tracks the light beam moves based on the count of the counting unit. The invention is characterized in that it has means (configuration of claim 6).

[For production]

According to the optical disc of claim 1, the mark indicating the address is formed as a part of the pregroove, and the pregroove is formed in a spiral or concentric shape so as not to be interrupted in the circumferential direction. , when the light beam crosses the track, it always crosses the pregroove; conversely, it is impossible for the light beam to cross the track but not cross the pregroove. This makes it possible to accurately detect the number of tracks crossed by the light beam.

According to the optical disc according to claim 2, the pregroove is formed so as not to be interrupted in the circumferential direction as described above, so that when the light beam crosses the track, it always crosses the pregroove. , it becomes possible to accurately detect the number of tracks crossed.

Further, it is possible to perform soft formatting by reading an index mark recorded as a part of a pregroove and writing address information and the like onto the optical disc using the index mark as a reference by an optical disc device. This makes it possible to format the optical disc in a desired format.

According to the optical disc of claim 3, information marks are pre-recorded in the first area and used as a read-only area, while only index marks are pre-recorded in the second N area, Soft formatting is performed by the optical disc device using the index mark as a reference, and recording, reproduction, or erasing can be performed based on the soft formatting.

The information mark in the first area and the index mark in the second N area are both formed as part of the pregroove, and since the pregroove is formed so as not to be interrupted in the circumferential direction of the optical disc, the light beam is It will be possible to accurately detect the number of times a track is crossed.

According to the optical disc device of claim 4, an optical disc on which a mark indicating address information is recorded as part of a pregroove by wobbling or the like is used, and the address information is reproduced by a reproducing means during recording or reproduction. At the same time, when the optical head moves in the radial direction of the optical disk, the track crossing detection means detects the crossing of the pregroove of the optical beam based on the reflected beam from the optical disk, detects the crossing of the track, and counts the number of track crossings. The optical head is moved to the target track while calculating the number of tracks to which the light beam is to be moved by the optical head moving means based on the count value of the counting means. In this case, since the pregroove of the optical disc is formed without interruption in the circumferential direction, the number of track crossings can be accurately detected.

According to the optical disc device of claim 5, an optical disc is used in which an index mark, which serves as a reference for soft formatting, is recorded as a part of a pregroove by wobbling or the like, and the index mark detecting means detects a reflected beam from the optical disc. Based on the index mark detection signal from the index mark detection means, the formatting means determines a reference position for soft formatting, and performs soft formatting of the optical disc. Recording and playback can be performed based on soft formatted address information. Further, when the optical head moves in the radial direction of the optical disk, the track crossing detection means detects the crossing of the track by the crossing of the pregroove of the optical beam based on the reflected beam from the optical disk, and the counting means detects the crossing of the track based on the reflected beam from the optical disk. The optical head can be moved to the target track by the optical head moving means while counting the number of track crossings and calculating the number of tracks to which the light beam moves based on the count of the counting means.

In this case, since the pregroove is formed without interruption in the circumferential direction of the optical disc, the number of times the track is crossed can be detected accurately.

According to the optical disc device of claim 6, an information mark is formed in advance in the first fiJf area as a read-only area integrally with the pregroove by wobbling of the pregroove, etc. An optical disc on which an index mark is formed as a part of a pregroove is used in the area, and the information mark is read out by a reproducing means based on the reflected beam from the first area to reproduce the information, and the information is reproduced in the second area. An index mark is detected by the index mark detection means based on the reflected beam from the index mark detection means, a reference position for soft formatting is determined by the formatting means according to the index mark detection signal from the index mark detection means, and a reference position for soft formatting is determined by the formatting means. After performing soft formatting of the area, information can be recorded, reproduced, or erased in the second area based on this soft formatting.

Further, when the optical head moves in the radial direction of the optical disk, the track crossing detection means detects the crossing of the track by the crossing of the pregroove of the optical beam based on the reflected beam from the optical disk, and the counting means detects the crossing of the track based on the reflected beam from the optical disk. The optical head can be moved to the target track by the optical head moving means while counting the number of track crossings and calculating the number of tracks to which the light beam moves based on the count of the counting means. In this case, since the pregroove is formed without interruption in the circumferential direction of the optical disc, the number of times the track is crossed can be detected accurately.

[Embodiment 1] An embodiment of the present invention will be described below based on FIGS. 1 to 19.

As shown in FIG. 10, the optical head 20 is driven in the radial direction of a magneto-optical disk 22 (optical disk) by a linear motor 21 as an optical head moving means. The laser beam emitted from the optical head 20 is irradiated onto the magneto-optical disk 22, the reflected beam is converted into an electric signal A by the photodiode 26 (see FIG. 11) in the optical head 20, and the electric signal A is sent to the reproducing circuit 23. guided by. When seeking to move the optical head 20 in the radial direction of the magneto-optical disk 22, the reproduced signal is guided to the counter 24 (counting means) as a digital track crossing signal B, and the number of times the optical head 20 crosses the track is counted (hereinafter referred to as , this counting operation is called track counting).

The count value data C is led to the seek control circuit 25, and an optical head control signal is sent to the linear motor 21 while the seek control circuit 25 confirms the track position of the optical head 200 passing through. As described above, the optical head 20
moves in the radial direction of the magneto-optical disk 22, and a target track is sought.

FIG. 11 shows a portion of a magneto-optical disk device that performs track counting.

In the figure, the reflected beam from the optical head 20 is received by a photodiode 26 in the optical head 20,
It is converted into an electrical signal A. The electric signal A is amplified by the amplifier 27 in the reproduction circuit 23, and the output signal E of the amplifier 27 is
is input to the plus input terminal of the comparator 28. A comparison voltage ■ is applied to the negative input terminal of the comparator 28. is input.

The output signal of comparator 28 is sent to counter 24 and demodulation circuit 30. The demodulation circuit 30 demodulates the address information recorded on the magneto-optical disk 22 with modulation such as bi-phase mark modulation based on the above output signal. Thus, the output signal of comparator 28 is used as track crossing signal B and address information signal F. Note that the pregroove 35 on the magneto-optical disk 22 will be described later.

The format of the magneto-optical disk 22 will be explained with reference to FIG. A concentric or spiral track 31 is formed in advance on the magneto-optical disk 22, and the track 31 is divided into a plurality of sectors 32, 32, . . . . Each sector 32 includes a header portion 33 in which address information of the track 31 and sector 32 is recorded in a preformat format when the magneto-optical disk 22 is manufactured, and data for recording, reproducing, or erasing information by the magneto-optical disk device. It is composed of a section 34.

FIG. 7 shows an enlarged view of the track 31 in the data section 34. As shown in FIG. Each track 31 is formed between pregrooves 35 on both sides. When recording information in the data section 34, the laser beam 36 is moved relative to the track 31 in the direction of arrow β, and a mark 37 is recorded using a magneto-optical method. Although not shown in FIG. 10, the magneto-optical disk device includes a magnetic field generating section in addition to the optical head 20. At the time of reproduction or erasure, the mark 37 is reproduced or erased while similarly moving the laser beam 36 relatively in the direction of the arrow β.

When seeking, the laser beam 36
Move in the direction of arrow α while crossing... At this time,
The output signal E (see FIG. 8) of the amplifier 27 decreases in level when crossing the pregrooves 35, 35, . . . .

Therefore, at the time of seek, the output signal E (see (a) in FIG. 9) of the amplifier 27 (FIG. 11) is compared to the voltage (2) in the comparator 28. When slicing is performed, the above-mentioned track crossing signal B is obtained. The track crossing signal B is the optical head 2
The level rises and falls as many times as 0 crosses tracks 31, 31, and so on.

This track crossing signal B is input to a counter 24 shown in FIG.
By inputting , the seek control circuit 25 can accurately seek a target track on the magneto-optical disk 22 while counting the number of tracks moved by the optical head 20 .

Here, since the mark 37 is recorded using a magneto-optical method, it can be separated from the track crossing signal B, and the signal from the mark 37 will not be mixed into the track crossing signal B. This will be explained using FIG. 13.

FIG. 13 shows in detail the peripheral equipment of the photodiode 26 in FIG. 11. The reflected beam from the magneto-optical disk 22 is split by a polarizing beam splitter 38 into two detected beams GH having different polarization planes.

These two detected lights GH are converted into electric signals Aa-Ab by photodiodes 26a and 26b, respectively, and inputted to an addition amplifier 27a and a subtraction amplifier 27b, respectively. As a result, signals from the pregroove 35 and marks 40, which will be described later, appear in the output signal Ea of the summing amplifier 27a, but signals from the mark 37 recorded by the magneto-optical method do not appear.

On the other hand, the signals from the pregroove 35 and the mark 40 do not appear in the output signal Eb of the subtraction amplifier 27b, but the signal from the mark 37 recorded by the magneto-optical method appears.

Therefore, the output signal Ea of the summing amplifier 27a is used as a track crossing signal B and the address information signal F, and the output signal Eb of the attenuation amplifier 27b is used as an information signal by magneto-optical recording.

Next, FIG. 1 shows a track 31 in a header portion 33. As shown in FIG.

Similar to the data section 34, the track 31 is formed sandwiched between two pregrooves 35. In the header part 33, the pregrooves 35 on both sides of the track 31 are wobbled (displaced in the radial direction) symmetrically to each other by a width ΔW toward the outer or inner circumference of the magneto-optical disk 22. As a result, a mark 40 indicating address information is formed. This address information is recorded after performing appropriate modulation such as bi-phase mark modulation. Note that the pregroove 35 in the header portion 33 and the data portion 34 is formed so as not to be interrupted in the circumferential direction. That is, when the track 31, in other words, the pregroove 35 is formed in a spiral shape, the pregroove 3
5 is formed as one completely continuous groove, and when the track 31 and the pregroove 35 are formed concentrically, each pregroove 35 is formed so that there is no discontinuity within one circumference of the disk. be done.

When recording, reproducing, or erasing information using the magneto-optical method,
The laser beam 36 moves along the track 31 in the direction of arrow β, and address information is read from the mark 40 on the header portion 33. Then, the data section 34 at a predetermined address
Recording, playback, or erasure is performed.

On the other hand, when seeking, the laser beam 36
Move in the direction of arrow α while crossing.

At this time, the level of the output signal E of the amplifier 27 (see FIG. 2) decreases when it passes through the pregroove 35. As a result, each time one track 31 is crossed, the level of the track crossing signal B obtained by binarizing the output signal E increases and decreases once. Since the mark 40 is formed as a part of the pre-groove 35, there are no uneven parts other than the pre-groove 35, and the pre-groove 35 is not interrupted in the circumferential direction. Each time the head 20 crosses the track 31, the level faithfully rises and falls. This allows the counter 24 to accurately count the number of track crossings and to accurately seek a predetermined track 31.

FIG. 3 shows a modification of the mark 40 on the header portion 33. Here, pregroove 3 is formed on both sides of track 31.
5 and 35 are wobbling in the same direction (inner circumferential side or outer circumferential side) by a width ΔW.

FIG. 5 shows another modification in which the widths of the pregrooves 35 on both sides of the track 31 are changed by ΔW.

Even in these modified examples, there are no uneven parts other than the pre-groove 35 (and the pre-groove 35 is not interrupted in the circumferential direction), so the output signal E of the amplifier 27 (see FIGS. 4 and 6) is 1 for each time Groove 35 is crossed.
The number of times the track is crossed can be accurately counted based on the track crossing signal B obtained by binarizing the output signal E.

FIG. 14 is a flowchart regarding the seek operation.

When an access operation is instructed, a seek operation is first started, the linear motor 21 is driven (Sl), and the optical head 20 is moved to the target track 31 side (S2).
.

Then, a track crossing signal B is generated (33), and the number of tracks 31 crossed is counted by the counter 24 (S4). Further, the seek control circuit 25 determines whether the number of track crossings counted by the counter 24 has reached the target value (S5), and if it has not reached the target value, the state returns to Sl and the linear motor 21 is further driven. be done.

On the other hand, if the number of tracks crossed has reached the target value, the seek operation is ended, and then the search operation is started.

Incidentally, in the explanation using FIGS. 1 to 9, for simplicity, it is assumed that the laser beam 36 crosses the track 31 at a substantially right angle during seek.

However, in reality, since the magneto-optical disk 22 is rotating even during seek, the laser beam 36 crosses the track 31 diagonally.

At this time, even if the laser beam 36 diagonally crosses the data section 34, the track crossing signal B is not disturbed, but as shown in FIG. 15(b) due to the relationship between the inclination angle θ of the laser beam 36 with respect to the track 31 and the width ΔW of the wobbling at the mark 40.
The output signal E of the amplifier 27 is disturbed as shown in FIG.
Track crossing signal B may be disturbed.

That is, the smaller the inclination angle θ of the laser beam 36,
Furthermore, the larger the wobbling width ΔW in the mark 40, the more likely the output signal E of the amplifier 27 will be disturbed.

Therefore, it is preferable to make the wob ring width ΔW as small as possible, as shown in FIG. 16(a). On the other hand, when the wobbling width ΔW decreases, the level of the address information signal F decreases, as shown by the dotted line in FIG. 17, and the S/N of the address information signal F decreases (see Table 1).

Therefore, it is necessary to determine the wobbling width ΔW in consideration of the balance between the S/N of the address information signal from the mark 40 and the track count accuracy.

Note that instead of the configuration shown in FIG. 11, as shown in FIG. 18, a hysteresis comparator 41 is arranged in parallel with the comparator 28, and the output signal of the hysteresis comparator 41 is inputted to the counter 24 as the track crossing signal B. By doing so, the accuracy of track counting can be improved. Note that the hysteresis comparator 41 is set so that the threshold value when its output is reversed from low level to high level is higher by Δy than the threshold value when its output is reversed from high level to low level. It is.

Waveforms generated by the circuit of FIG. 18 are shown in FIG. 16(b) and (C). Here, since the wobbling width ΔW of the mark 40 is smaller than in the case of FIG. 15, the disturbance in the track crossing signal B is smaller than in the case of FIG. By Δy, for example, it is possible to prevent the track crossing signal B output from the hysteresis comparator 41 from being disturbed at the waveform disturbance region Z of the output signal E of the amplifier 27.

Note that, assuming that the amplitude of the output signal E of the amplifier 27 is Xt, the amount of disturbance of the output signal E is Xs, and the hysteresis level is Δy, then Xt>Δy>Xs may be satisfied.

15 and 16 show the case where the laser beam 36 diagonally crosses the track 31 having the mark 40 in the pattern shown in FIG. 3, but the mark 40 in the pattern shown in FIG. The same applies when the laser beam 36 obliquely traverses the track 31 having the number 40.

In the above embodiment, the track counting section shown in FIG. 19 may be used instead of the track counting section shown in FIG. 11.

That is, here, the photodiode 26 in FIG.
Instead, a two-divided photodiode 42 is used, and two output signals I-J from each light receiving section of the two-divided photodiode 42 are inputted to the plus input terminal and the minus input terminal of the differential amplifier 43, respectively. The output signal E of the differential amplifier 43 is a generally known tracking error signal, which is also used for track servo of the laser beam 36. The output signal E of the differential amplifier 43 is input to the plus input terminal of the comparator 44, and the minus input terminal of the comparator 44 is grounded. The output signal of the comparator 44 is led to the counter 24 as a track crossing signal B;
Perform track count.

[Embodiment 2] Next, another embodiment of the present invention will be described based on FIGS. 20 to 25.

In the first embodiment described above, the address information is formed in advance in the header part 33 of each sector 32 by wobbling or the like, but in this embodiment, the address information is formed in the header part 33 based on the index mark 53 formed in advance. Address information is soft formatted using a magneto-optical method.

FIGS. 20(a) and 20(b) show a magneto-optical disk 52 employing the soft formatting method of this embodiment. A concentric or spiral trunk 31 is formed on the magneto-optical disk 52 and is partitioned by pregrooves 35 . An index mark 53 is previously formed on a part of the track 31 by, for example, wobbling the pregrooves 35 on both sides of the trunk 31 in the same direction. The index mark 53 is
For example, one track 31 (one track of the magneto-optical disk 52)
The length along the track 31 is approximately 1 μm to approximately 100 μm.
m (when the wavelength of the laser beam is 800 nm and the Na content of the objective lens is 0°5).

In the magneto-optical disk IT shown in FIGS. 21 and 22, when detecting the index mark 53, the optical head 200 and the semiconductor laser 54 are
(FIG. 20) is irradiated with a laser beam, and the reflected beam is received by the photodiode 26. The electrical signal A from the photodiode 26 is sent to the reproducing circuit 23.

In the reproduction circuit 23, the above electric signal A is transmitted to the amplifier 27.
The output signal E of the amplifier 27 is input to the plus input terminal of the comparator 28. On the other hand, the comparison voltage ■ is applied to the negative input terminal of the comparator 28. is input, and the output signal E of the amplifier 27 is binarized. In addition,
(C) in FIG. 20 shows how the signal from the index mark 53 included in the output signal E is binarized at the slice level v0.

The output signal of comparator 28 is conducted as track crossing signal B to counter 24, where the number of track crossings is counted as described above.

Further, the output signal of the comparator 28 is led as an index mark signal to an index mark detection circuit 55, where the index mark 53 is detected and an index mark detection signal is output. The index mark detection signal is led to a formatting circuit 56, and a formatting start position or reference position is determined. In accordance with this, the format data signal M is sent to the semiconductor laser 54 of the optical disc 20, and the magneto-optical disk 52 is formatted.

In FIG. 20, the index mark 53 is recorded by wobbling only once, but as shown in FIG. 23 (a), the index mark 53 may be recorded by wobbling a plurality of times. In this case as well, the signal read from the index mark 53 (see 23rd part (b)) is binarized by the comparator 28, and the index mark detection circuit 55 can detect the index mark 53. By forming the index mark 53 by wobbling a plurality of times in this manner, detection errors can be reduced compared to the case shown in FIG. 20(a).

Note that the index mark 53 is formed by wobbling the pregrooves 35 on both sides of the track 31 in opposite directions, similar to the mark 40 in FIG. Similarly, it can also be formed by polarizing the widths of the pregrooves 35 on both sides of the track 31.

Next, FIG. 24 shows an example of the format of the Nth track 31 of the magneto-optical disk 52. In the same figure (a)
This is a case where the header part 33 of each sector 32 is preformatted with the mark 40 as in the first embodiment.

On the other hand, in this embodiment, as shown in (b) in the figure, when manufacturing the magneto-optical disk 52, one
The index mark 53 is simply formed at a location, that is, at the beginning position of the track 31.

When recording information on the magneto-optical disk 52, first, soft formatting is performed. At this time, as mentioned above,
If a signal from the index mark 53 is present in the index mark signal output from the reproducing circuit 23 based on the reflected beam from the magneto-optical disk 52, an index mark detection signal L (in FIG. 24) is output from the index mark detection circuit 55. (d)) is output.

The starting position of soft formatting is determined based on this index mark detection signal, and a laser beam is emitted from the semiconductor laser 54 ((e) in FIG. 24).
), the addresses of the track 31 and sector 32 are written in the header part 33 of each sector 32, and soft formatting is performed ((C) in FIG. 24). In addition, in FIG. 24, one track 31 has five sectors 32.3.
2... is included.

After performing soft formanting as above,
Track 3 by playing the information in the header part 33.
1 and the address of the sector 32, information can be recorded/reproduced or erased in the data section 34. In addition,
In the above example, one index mark 53 is formed on each track 31.
If a plurality of index marks 53 are formed on each index mark 1, the accuracy of soft formatting can be improved.

FIG. 25 is a flowchart regarding soft formatting.

When soft formatting is started for the Nsth to Neth tracks 31, 3, etc., first, the soft formatting start track number Ns is assigned to the track number N, and the start track is determined. be done (
Sll). Next, the controller accesses the Ns-th track 31 and waits until the index mark 53 of this track 31 is detected (S12). Nsth track 31
If the index mark 53 is detected, soft formatting for one track is performed for the Ns-th track 31 (S13).

Next, 1'' is added to the track number, and it is determined whether the track number is larger than the number Ne of the track where soft formatting has been completed (S14), and if the track number is larger than Ne, the soft formatting is completed. be done.

On the other hand, if the track number is less than or equal to Ne, the process returns to S12 and the same process as above is repeated.

By the way, although a duplicate explanation will be omitted, in this embodiment, as in the first embodiment, the seek operation is controlled based on the counter 24 that counts the number of tracks 310 that the optical head 54 traversed during seek, and the count value of the counter 24. A seek control circuit 25 (see FIG. 10) and the like are provided. Also in this embodiment, as in the first embodiment, the pregroove 3
5 is formed so as not to be interrupted in the circumferential direction of the magneto-optical disk 52.

Therefore, when seeking, that is, when the optical head 54 moves in the radial direction of the magneto-optical disk 52, the optical head 54
4 crosses one pregroove 35 each time it crosses one track 31. Further, since the index mark 53 is formed by wobbling or the like of the pregroove 35, the level of the track crossing signal B does not rise or fall at a portion other than the pregroove 35. This makes it possible to accurately count the number of tracks 31 traversed by the optical head 20, as in the first embodiment.

Further, address information and data information are recorded in the header part 33 and the data part 34 using a magneto-optical method, and information based on the magneto-optical method and information due to unevenness such as the track crossing signal B are separated and detected. What can be done is Example 1
This is the same as that explained using FIG.

Furthermore, if the laser beam diagonally crosses the index mark 53 (FIG. 20, FIG. 23, FIG. 1 or FIG. 5) in the pre-groove 35 during seek, the output signal E of the amplifier 27 is disturbed, and the output signal E of the amplifier 27 is disturbed. As a result, the reason why the track crossing signal B may be disturbed is that in the first embodiment, the laser beam 36 is caused by the mark 40 in the pregroove 35.
This is similar to the possibility that the track crossing means B may be disturbed when crossing the section diagonally.

In this case, as in the first embodiment, the index mark 53
If the wobbling width ΔW is made smaller, disturbances in the track crossing means B become less likely to occur, but on the other hand, a problem arises in that the S/N of the signal from the index mark 53 decreases, so ΔW is determined by considering the balance between the two. There is a need to. Further, as in the first embodiment, it is preferable to arrange a hysteresis comparator 41 (see FIG. 18) upstream of the counter 24 that counts the number of track crossings.

[Example 3] Next, another embodiment of the present invention will be described.

As shown in FIG. 26, the recording area of the magneto-optical disk 72 is divided into a first area 73 (preformat area) on the inner circumference side and a second area 74 (soft format area) on the outer circumference side. First area 73 and second area 7
Similarly to Embodiments 1 and 2, tracks 31 are formed in advance by pregrooves 35 and 35 (see FIG. 1, FIG. 3, FIG. 5, or FIG. 7).

In the first area 73, address information is recorded at the time of disk manufacturing by a mark 40 formed by wobbling pregrooves 35, 35 or changing the width in the header part 33 of each sector 32. 3
Data information is recorded at the time of disk manufacture by an information mark 75 formed by wobbling the pregrooves 35 and 35 or changing the width in the data area 34 of 2 (
(See (a) in Figure 24).

On the other hand, in the second area 74, as in the second embodiment, only one index mark 53 for each sector 32 is preformatted by wobbling or changing the width of the pregrooves 35 (see FIG. 24). (see (b)). Based on the detection of the index mark 53, the header part 33 of each sector 32 in the second N area 74 is soft-formatted, and then information is recorded, reproduced, or erased in each data section 34. There is.

In an optical disk device that can share multiple types of optical disks, such as read-only optical disks, so-called write-once optical disks, and rewritable optical disks such as the magneto-optical disk 72, the optical disk is placed in the first N area 73 of the magneto-optical disk 72. If you record the type of disk, that is, that it is a magneto-optical disk, and the recording conditions, the optical disk device will
91 area 73, determines that the type of optical disk is a magneto-optical disk 72, sets recording conditions, performs soft formatting on the magneto-optical disk 72, and then records/reproduces or erases information. It can be carried out.

In addition, when used as a recording medium for a computer system, system files such as O3 may be recorded in the first area 73 in a preformat format, or information that does not need to be erased or rewritten, such as a dictionary file, may be recorded in the first area 73. Information can be recorded in the first area 73 and information that needs to be erased or rewritten, such as user files, can be recorded in the second area 74. In this way, the magneto-optical disk 72 is
By dividing into the area 73 and the second area 74, versatility can be increased.

By the way, the optical disc device of this embodiment is also similar to that of the first embodiment.
Similar to 2, track 3 is traversed by the optical head when seeking.
It includes a counter 24 for counting the number of 1s, a seek control circuit 25, and the like. Also, the 191st area 73 and the 2nd area
The pre-groove 35 in the N area 74 is formed so as not to be interrupted in the circumferential direction, and the mark 40 (
header section 33) and information mark 75 (data section 34)
) and the index mark 53 of the second fil area 74
is formed by wobbling of the pre-groove 35, etc., and since there is no part other than the pre-groove 35 that increases or decreases the level of the track crossing signal B, the track 31 that the optical head crosses in the first and second regions 73 and 74 The number of lines can be detected accurately.

In the third embodiment, the second area 74 is a soft format area, but the address information is preformatted in the header part 33 of the second area 74 by wobbling or the like, and the data part 34 of the second N area 74 is Alternatively, data information may be recorded, reproduced, or erased using a magneto-optical method.

Furthermore, in the third embodiment, the area is divided into the first and second areas 73 and 74, but the area may be further divided into a larger number of areas.

Furthermore, although the above embodiments have been explained using magneto-optical disks, the present invention can also be applied to other rewritable optical disks such as phase change optical disks, write-once optical disks, etc. .

〔Effect of the invention〕

As described above, the optical disc according to the present invention includes a pregroove that forms a track for following a light beam;
A mark indicating an address is formed by wobbling the pregroove or changing the width of the pregroove, and the pregroove including the mark is formed concentrically or spirally without interruption in the circumferential direction. (Claim 1).

This ensures that when the light beam crosses the track it always crosses the pregroove, and conversely it is impossible for the light beam to cross the track but not cross the pregroove; This makes it possible to accurately detect the number of tracks.

Another optical disc of the present invention includes a pregroove that forms a track for following a light beam, and soft formatting (soft formatting), which is formed by wobbling the pregroove or changing the width of the pregroove.
(Means formatting by writing address information etc. using an optical disc device after manufacturing an optical disc)
and an index mark indicating a reference position, and a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction (claim 2).

As a result, when the light beam crosses a track, it always crosses the pregroove, making it possible to accurately detect the number of tracks crossed.

In addition, the index mark recorded as part of the pregroove is read out, and the optical disc device writes address information etc. onto the optical disc using this index mark as a reference and performs soft formatting, thereby formatting the optical disc in the desired format. You will be able to matting.

Still another optical disc of the present invention has a first area in which information is recorded in advance, and a second area in which information can be recorded, reproduced, or erased, and the first area has an area for following a light beam. It has a pre-groove forming a track and an information mark recorded in advance by wobbling the pre-groove or changing the width of the pre-groove,
The pregroove including the information mark is formed concentrically or spirally without interruption in the circumferential direction, and the second area includes a pregroove that forms a track for following the light beam, and a pregroove that forms a track for following the light beam. It has an index mark that is formed by wobbling or changing the width of the pregroove and indicates the reference position for soft formatting, and the pregroove including the index mark is formed in a concentric or spiral shape without interruption in the circumferential direction. (claim 3).

As a result, while the first area is used as a read-only area, soft formatting is performed on the second area by the optical disc device using the index mark as a reference, and recording, playback, or erasing can be performed based on the soft formatting.

The information mark in the first area and the index mark in the second area are both formed as part of the pregroove, and the pregroove is formed so as not to be interrupted in the circumferential direction of the optical disc, so that the light beam is It will be possible to accurately detect the number of times a track is crossed.

The optical disc device according to the present invention includes a pregroove that forms a track for following a light beam, and a mark indicating an address on the optical disc that is formed by wobbling the pregroove or changing the width of the pregroove. The method uses an optical disc in which a pregroove including the mark is formed concentrically or spirally without interruption in the circumferential direction, reads the mark based on a beam reflected from the optical disc, and reads address information. a reproducing means for reproducing data; a track crossing detecting means for detecting a track crossing by a light beam crossing a pregroove based on a reflected beam from the optical disc when the optical head moves in the radial direction of the optical disc; The optical head moving means moves the optical head to the target track while calculating the number of moving tracks of the light beam based on the count value of the counting means (claim 4). section).

This makes it possible to obtain address information by reading out the mark using the reproducing means during recording or reproduction. Here, since the pregroove of the optical disc is formed without interruption in the circumferential direction, the track crossing detection means can accurately detect the track crossing, and therefore the counting means can accurately detect the number of crossings. , it becomes possible to reliably move the optical head to a predetermined track.

Another optical disc device of the present invention includes a pregroove that forms a track for following a light beam, and a reference position for soft formatting that is formed by wobbling the pregroove or changing the width of the pregroove. An optical disc having an index mark indicating the index mark, in which a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction, is used, and the index mark is determined based on the reflected beam from the optical disc. index mark detection means for detecting and outputting an index mark detection signal;
A formatting means that determines a reference position for soft formatting based on the index mark detection signal and formats the optical disc; a track crossing detection means for detecting the crossing of the track by the light beam crossing the pregroove; a counting means for counting the number of track crossings; and a counting means for counting the number of tracks traveled by the light beam based on the count of the counting means The optical head moving means moves the optical head to the target track while calculating (
(Claim 5).

As a result, the index mark is detected by the index mark detection means based on the reflected beam from the optical disc, and the reference position for soft formatting is determined by the formatting means based on the index mark detection signal from the index mark detection means. Decide and perform soft formatting of the optical disc.
Thereafter, since recording and reproduction are performed based on the soft formatted address information, formatting can be performed in a desired format.

In addition, since the pre-groove of the optical disk is not interrupted in the circumferential direction, when the optical head moves in the radial direction of the optical disk, the track crossing detection means accurately detects the track crossing, and the counting means detects the number of track crossings. can be accurately counted and reliably moved to a predetermined track.

Still another optical disc device of the present invention has a first area in which information is recorded in advance, and a second area in which information can be recorded, reproduced, or erased, and the first area is configured to follow a light beam. a pre-groove forming a track, and an information mark recorded in advance by wobbling this pre-groove or changing the width of the pre-groove, and the pre-groove including the information mark is discontinued in the circumferential direction. The second region includes a pre-groove that forms a track for the light beam to follow, and the pre-groove is wobbled or the width of the pre-groove is changed. The optical disc has an index mark indicating the reference position for soft formatting, and a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction. a reproducing means for reading out the information mark based on the reflected beam from the first area and reproducing the information; and a reproducing means for detecting the index mark based on the reflected beam from the second area of the optical disc and outputting an index mark detection signal. an index mark detection means; a formatting means for determining a reference position for soft formatting based on the index mark detection signal and performing soft formatting on a second area of the optical disc; a track crossing detection means for detecting the crossing of the track by the optical beam crossing the pregroove based on the reflected beam from the optical disk; a counting means for counting the number of track crossings; and a counting means for the counting means. The optical head moving means moves the optical head to the target track while calculating the number of tracks to which the light beam moves based on numerical values (Claim 6).

Thereby, in the first area of the optical disc, address information can be obtained by reading the mark by the reproducing means during recording or reproduction. On the other hand, the second
In the area, the index mark is detected by the index mark detection means based on the reflected beam, and a reference position for soft formatting is determined by the formatting means based on the index mark detection signal from the index mark detection means. Since soft formatting is performed and subsequent recording and reproduction are performed based on the soft formatted address information, formatting can be performed in a desired format.

Furthermore, since the pregrooves in the first and second regions are formed without interruption in the circumferential direction, the track crossing detection means can accurately detect track crossings, and therefore the counting means can accurately detect the number of crossings. Because it can be done,
It becomes possible to reliably move the optical head to a predetermined track.

[Brief explanation of drawings]

1 to 19 show an embodiment of the present invention. FIG. 1 is a schematic plan view showing a pregroove having wobbling formed on a magneto-optical disk. FIG. 2 is an explanatory diagram showing a reproduced signal when a laser beam traverses the pregroove shown in FIG. 1. FIG. 3 is a schematic plan view showing a pregroove with wobbling formed on a magneto-optical disk. FIG. 4 is an explanatory diagram showing a reproduced signal when the laser beam traverses the pregroove shown in FIG. 3. FIG. 5 is a schematic plan view showing a pregroove having a varying width formed on a magneto-optical disk. FIG. 6 is an explanatory diagram showing a reproduced signal when the laser beam crosses the pregroove shown in FIG. 5. FIG. FIG. 7 is a schematic plan view showing a pregroove without wobbling formed on a magneto-optical disk. FIG. 8 is an explanatory diagram showing a reproduced signal when the laser beam traverses the pregroove shown in FIG. 7. FIG. 9 is an explanatory diagram showing the output signal of the amplifier and the track crossing signal. FIG. 10 is an explanatory diagram showing a schematic configuration of a magneto-optical disk device. FIG. 11 is a block diagram of the main parts of the magneto-optical disk device. FIG. 12 is an explanatory diagram showing the structure of a magneto-optical disk. FIG. 13 is an explanatory diagram showing the detailed structure of the peripheral portion of the photodiode. FIG. 14 is a flowchart showing the procedure of a seek operation. FIG. I5 is an explanatory diagram showing how the laser beam diagonally crosses the pregroove. FIG. 16 is an explanatory diagram showing how the laser beam diagonally crosses the pregroove when the width of the wobbling is reduced. FIG. 17 is an explanatory diagram showing changes in the level of the address information signal depending on the wobbling width. FIG. 18 is a block diagram showing a modification of the reproduction circuit. FIG. 19 is an explanatory diagram showing a modification of the peripheral portion of the photodiode. FIGS. 20 to 25 show other embodiments of the present invention. FIG. 20 is an explanatory diagram showing the configuration of a pregroove of a magneto-optical disk. FIG. 21 is a block diagram of main parts of the magneto-optical disk device. FIG. 22 is an explanatory diagram of the main parts of the magneto-optical disk device. FIG. 23 is an explanatory diagram showing another configuration of the pregroove of the magneto-optical disk. FIG. 24 is an explanatory diagram showing a schematic configuration of a magneto-optical disk. FIG. 25 is a flowchart showing the procedure of formatting operation. FIG. 26 is an explanatory diagram showing a schematic configuration of a magneto-optical disk in still another embodiment of the present invention. 27 to 32 show conventional examples. FIG. 27 is a schematic plan view showing a pregroove of an optical disc. FIG. 28 is an explanatory diagram showing a reproduced signal when the laser beam traverses the pregroove shown in FIG. 27. FIG. 29 is a schematic plan view showing another pregroove of the optical disc. FIG. 30 is an explanatory diagram showing a reproduced signal when the laser beam traverses the pregroove shown in FIG. 29. FIG. 31 is a schematic plan view of a floppy disk. FIG. 32 is a schematic front view of the floppy disk device. 20 is an optical head, 21 is a linear motor (optical head moving means), 22, 52, and 72 are magneto-optical disks (optical disks), 24 is a counter (counting means), 31 is a track, 32 is a sector, and 33 is a part of a header. , 34 is the data section,
35 is a pregroove, 40 is a mark, 53 is an index mark, 55 is an index mark detection circuit (index mark detection means), 73 is a first area, and 74 is a second area.
The area 75 is an information mark. Patent Applicant Sharp Co., Ltd. No. 1 (9) No. 1; 4 72 Fig. 3 Fig. 4m Fig. 5 Fig. 6 Fig. Jt) Fig. 7 Fig. 8' Fig. 9 Fig. 101! Fig. 12 ” and the lid 32 No. 131! * Fig. 14 Fig. 15 and Fig. 16 Figure 29 ys30v4 131: W432 diagram

Claims (1)

[Claims] 1. A pregroove that forms a track for following a light beam, and a mark indicating an address formed by wobbling the pregroove or changing the width of the pregroove. . An optical disc characterized in that the pregroove including the mark is formed concentrically or spirally without interruption in the circumferential direction. 2. It has a pregroove that forms a track for the light beam to follow, and an index mark that is formed by wobbling the pregroove or changing the width of the pregroove and indicating a reference position for soft formatting. . An optical disc characterized in that the pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction. 3. It has a first area where information is pre-recorded and a second area where information can be recorded, reproduced or erased, and the first area has a pre-groove that forms a track for following the light beam. , and an information mark recorded in advance by wobbling the pregroove or changing the width of the pregroove, and the pregroove including the information mark is formed in a concentric or spiral shape without interruption in the circumferential direction. At the same time, the second area includes a pregroove that forms a track for the light beam to follow, and a reference position for soft formatting that is formed by wobbling this pregroove or changing the width of the pregroove. What is claimed is: 1. An optical disc having a pre-groove including the index mark shown in FIG. 4. It has a pregroove that forms a track for the light beam to follow, and a mark that is formed by wobbling the pregroove or changing the width of the pregroove and indicating the address on the optical disk, and the mark is A reproducing means for reproducing address information by reading out the mark based on a reflected beam from the optical disc using an optical disc in which a pregroove is formed concentrically or spirally without interruption in the circumferential direction; and an optical head. track crossing detection means for detecting the crossing of the track by the light beam crossing the pregroove based on the reflected beam from the optical disk when the optical disk moves in the radial direction of the optical disk; and counting means for counting the number of track crossings; An optical disk device comprising an optical head moving means for moving the optical head to a target track while calculating the number of tracks to which the light beam moves based on the count value of the counting means. 5. It has a pregroove that forms a track for following the light beam, and an index mark that is formed by wobbling the pregroove or changing the width of the pregroove and indicating a reference position for soft formatting. , an optical disc in which a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction is used, the index mark is detected based on the reflected beam from the optical disc, and an index mark detection signal is generated. an index mark detection means for outputting; a formatting means for determining a reference position for soft formatting based on the index mark detection signal and soft formatting the optical disc; when the optical head moves in the radial direction of the optical disc; track crossing detection means for detecting track crossing by the light beam crossing the pregroove based on the reflected beam from the optical disk; counting means for counting the number of track crossings; An optical disk device comprising an optical head moving means for moving an optical head to a target track while calculating the number of tracks to which a beam moves. 6. It has a first area where information is pre-recorded and a second area where information can be recorded, reproduced or erased, and the first area has a pre-groove that forms a track for following the light beam. , and an information mark recorded in advance by wobbling the pregroove or changing the width of the pregroove, and the pregroove including the information mark is formed in a concentric or spiral shape without interruption in the circumferential direction. At the same time, the second area includes a pregroove that forms a track for the light beam to follow, and a reference position for soft formatting that is formed by wobbling this pregroove or changing the width of the pregroove. using an optical disc having an index mark indicated by the index mark, and in which a pregroove including the index mark is formed concentrically or spirally without interruption in the circumferential direction; reproducing means for reading out the information mark and reproducing the information; index mark detecting means for detecting the index mark based on a reflected beam from a second area of the optical disc and outputting an index mark detection signal; and detecting the index mark. A reference position for soft formatting is determined based on the signal, and the second
a formatting means for performing soft formatting of an area; and a track traversal device for detecting track crossing by a light beam crossing a pregroove based on a reflected beam from the optical disc when the optical head moves in the radial direction of the optical disc. The present invention includes a detection means, a counting means for counting the number of track crossings, and an optical head moving means for moving the optical head to a target track while calculating the number of tracks the light beam moves based on the count value of the counting means. Characteristic optical disc device.